U.S. patent number 9,693,852 [Application Number 14/217,017] was granted by the patent office on 2017-07-04 for embolic protection device.
This patent grant is currently assigned to MicroVention, Inc.. The grantee listed for this patent is MicroVention, Inc.. Invention is credited to Kaushik Joshi, Cang Lam, Jacqueline Macias, Priscilla Tsai, Arnold Tuason, Juan Valencia.
United States Patent |
9,693,852 |
Lam , et al. |
July 4, 2017 |
**Please see images for:
( Certificate of Correction ) ** |
Embolic protection device
Abstract
An embolic protection device includes an expandable and
contractible filter that can be supported by one or more struts.
The struts can be connected to the filter or interwoven into the
filter, so as to assist in the expansion and contraction of the
filter. In one embodiment, the proximal ends of the struts connect
to a joint that is fixed in position relative to a delivery wire,
while the distal end of the filter connect to a joint that slides
relative to the delivery wire.
Inventors: |
Lam; Cang (Tustin, CA),
Tsai; Priscilla (Rancho Santa Margarita, CA), Valencia;
Juan (Santa Ana, CA), Macias; Jacqueline (South Gate,
CA), Joshi; Kaushik (Tustin, CA), Tuason; Arnold
(Claremont, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
MicroVention, Inc. |
Tustin |
CA |
US |
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Assignee: |
MicroVention, Inc. (Tustin,
CA)
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Family
ID: |
51538560 |
Appl.
No.: |
14/217,017 |
Filed: |
March 17, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140288588 A1 |
Sep 25, 2014 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61799114 |
Mar 15, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F
2/0105 (20200501); A61F 2250/0017 (20130101); A61F
2230/0076 (20130101); A61F 2250/0039 (20130101); A61F
2230/008 (20130101); A61F 2230/0067 (20130101); Y10T
29/49826 (20150115); A61F 2230/0006 (20130101); A61F
2230/0078 (20130101); A61F 2230/005 (20130101); A61F
2002/016 (20130101); A61F 2210/0076 (20130101); A61F
2230/0008 (20130101) |
Current International
Class: |
A61M
29/00 (20060101); A61F 2/01 (20060101) |
Field of
Search: |
;606/200,108,191,194,195,198 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
European Patent Office, Supplementary European Search Report dated
Oct. 23, 2013 in European Patent Application No.
12749846.7-1506-2667925, 11 pages. cited by applicant .
WIPO, U.S. International Search Authority, International Search
Report and Written Opinion mailed Nov. 14, 2014 in International
Patent Application No. PCT/US2014/030738, 12 pages. cited by
applicant.
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Primary Examiner: Bui; Vy
Attorney, Agent or Firm: Inskeep IP Group, Inc.
Parent Case Text
RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application
Ser. No. 61/799,114 filed Mar. 15, 2013 entitled Embolic Protection
Device, which is hereby incorporated herein by reference in its
entirety.
Claims
What is claimed is:
1. An embolic protection device, comprising: an elongated delivery
wire; a filter connected to said elongated delivery wire; said
filter having an expanded configuration and a collapsed
configuration; a sliding joint connected to a distal end of said
filter and configured to slide relative to said elongated delivery
wire; a plurality of struts connected to said filter and oriented
proximally of said filter; a fixed joint connected to said
plurality of struts and that remains stationary relative to said
elongated delivery wire; and, a compression member disposed
distally of said filter on said elongated delivery wire and
connected to said sliding joint to bias said filter into an
expanded configuration.
2. The device of claim 1, wherein said filter member further
comprises a first mesh layer and a second mesh layer.
3. The device of claim 1, wherein said plurality of struts are
coupled to said filter near a proximal end of said filter.
4. The device of claim 1, wherein said distal end of said filter is
connected to said elongated delivery wire so as to slide relative
to said elongated delivery wire.
5. The device of claim 1, further comprising a rapid exchange
catheter disposed over said device.
6. The device of claim 1, wherein said filter comprises an
interwoven mesh formed of a first plurality of wires having a first
diameter and a second plurality of wires having a second diameter
that is larger than said first diameter.
7. The device of claim 1, wherein said filter comprises a heat-set
middle portion which is laterally compressed more than a distal
portion of said filter.
8. The device of claim 1, wherein said filter has a parabolic
shape.
9. The delivery device of claim 1, wherein said elongated delivery
wire further comprises a passage sized to accommodate a
guidewire.
10. The delivery device of claim 1, further comprising a delivery
catheter further having a selectively-openable distal end.
11. The device of claim 1, wherein said compression member is a
spring member, resilient polymer member, or an elastomeric
member.
12. The device of claim 1, wherein said compression member is
disposed between a distal second fixed joint and said distal
sliding joint; said distal sliding joint being connected to a
distal end of said filter.
13. The device of claim 1, wherein said plurality of struts are
each connected to said fixed joint and to a proximal end of said
filter.
14. The device of claim 13, wherein said plurality of struts are
biased to provide a radially expansive force on said proximal end
of said filter.
Description
BACKGROUND OF THE INVENTION
During certain surgical procedure, such as catheter-based
treatments, a physician's surgical tools can sometimes dislodge
embolic particles. These embolic particles typically include
thrombus, atheroma, and lipids, which, once dislodged, can cause
blockages in downstream vessels. Hence, these embolic particles can
result in serious surgical complications, such as stroke or even
death.
One method for reducing the risk of these complications is to
deploy an embolic filter downstream of a surgical treatment site,
thereby catching any particles that may become dislodged. Once
caught, the filter must be carefully closed and withdrawn from the
patient, such that the captured particles do not spill out.
SUMMARY OF THE INVENTION
One embodiment is directed to an embolic protection device
comprising a filter, one or more struts connected to said filter, a
delivery wire, a sliding joint, one or more fixed joints, and a
flexible member between said sliding joint and a fixed joint.
In one embodiment the embolic protection device includes a flexible
member which sits distal relative to the filter.
In another embodiment the embolic protection device includes a
flexible member which spans the length between the filter and the
struts
In another embodiment the embolic protection device includes a
flexible member which spans a portion of the length between the
filter and the struts.
In one embodiment the embolic protection device includes a sliding
joint and/or fixed joint that has a shape adapted to mate with a
delivery device used to deliver the embolic protection device
In one embodiment an embolic protection device includes a filter
wherein said filter is inverted.
In another embodiment an embolic protection device includes a
filter wherein said filter is everted.
In another embodiment, an embolic protection device includes a
rapid exchange delivery catheter.
In another embodiment, an embolic protection device includes a
fixed joint that can rotate relative to a delivery wire.
In another embodiment, an embolic protection device includes a
filter formed from a plurality of large wire and a plurality of
small wires. The large wires can additionally form the struts on
the device's proximal end. Additionally, a proximal fixed joint and
a distal sliding joint are disposed on a tube, through which a
delivery wire is disposed.
In another embodiment, an embolic protection device includes a
filter having a heat-set open-end portion having a relatively less
porous or more compressed configuration than the more distal
portions.
In another embodiment, an embolic protection device includes a
filter having a heat-set open-end portion having a relatively less
porous or more compressed configuration than the more distal
portions. As the filter reduces in diameter, the more-compressed
region more quickly reduces in diameter, partially closing around
the mouth of the filter.
In another embodiment, an embolic protection device includes a
filter having distal struts or loop shapes that assist in opening
and closing the filter.
In another embodiment, an embolic protection device is configured
to operate as a rapid exchange or monorail device, accommodating
both the delivery wire and the guidewire.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features and advantages of the invention
will be apparent and elucidated from the following description of
embodiments of the present invention, reference being made to the
accompanying drawings, in which:
FIGS. 1-3 illustrate an embolic protection device in an expanded
state.
FIGS. 4-6 illustrates an embolic protection device in a compressed
state (i.e. during delivery).
FIG. 7 illustrates a fixed joint used in an embolic protection
device.
FIG. 8-9 illustrate filters used in an embolic protection
device.
FIGS. 10-11 illustrate a filter and struts used in an embolic
protection device.
FIGS. 12-13 illustrate struts used in an embolic protection
device.
FIGS. 14-16 illustrate a sliding embolic protection device.
FIGS. 17-18 illustrate a catheter used with an embolic protection
device.
FIG. 19 illustrates an embolic protection device which is
rotatable.
FIGS. 20-24 illustrate several different rotatable joints.
FIGS. 25-26 illustrate an embolic protection device in an expanded
state.
FIGS. 27-28 illustrate magnified views of the filter of the device
from FIG. 25.
FIGS. 29-31 illustrate various views for creating the device of
FIG. 25.
FIG. 32 illustrates an embolic protection device having a parabolic
filter shape.
FIG. 33 illustrates an end view of a filter having a plurality of
loop-shaped struts.
FIGS. 34-35 illustrate an embolic protection device having outer,
"football" shaped struts.
FIG. 36 illustrates an embolic protection device.
FIGS. 37-40 illustrate cross sectional views of various rapid
exchange embolic protection devices.
FIGS. 41-44 illustrates side views of various rapid exchange
embolic protection devices.
FIGS. 44-45 illustrates a catheter-cutting device for opening a
distal end of a delivery device.
FIG. 46 illustrates a catheter-cutting device for opening a distal
end of a delivery device.
DESCRIPTION OF EMBODIMENTS
Specific embodiments of the invention will now be described with
reference to the accompanying drawings. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. The terminology used in the
detailed description of the embodiments illustrated in the
accompanying drawings is not intended to be limiting of the
invention. In the drawings, like numbers refer to like
elements.
The terms thrombus, emboli, embolic particles, and similar terms
are used throughout this specification. Unless specifically noted
otherwise, these terms are used interchangeably and generally refer
to any unwanted, undesirable, or otherwise dangerous particle that
could be located or caused to locate within a vessel of a human
body.
The present specification and drawings contain several different
embodiments that each contain different elements and
configurations. While these specific embodiments have been
described, it should be understood that any of the elements and/or
configurations can be combined with any of the other embodiments
presented.
Embolic protection devices may be used to trap thrombus dislodged
during a thrombus removing procedure. In one example, an embolic
protection device is placed distal of the target area. A balloon
and/or stent are used to expand the clogged vessel, and the embolic
protection device catches any dislodged thrombus to prevent it from
migrating downstream.
FIGS. 1-3 show various embodiments for the embolic protection
device that each have an expanded configuration for trapping
embolic particles and a contracted configuration which it adopts
when being delivered through a delivery device 30 (i.e.,
microcatheter) as shown in FIG. 4-6. In each of these embodiments,
the embolic protection devices 10, 11, and 13 sit over a delivery
wire 12 and include a filter 20 used to capture thrombus.
Preferably, the filter 20 is a braid or mesh formed from one or
more wires (e.g., wires composed of Nitinol, stainless steel,
cobalt chromium, and/or a polymer material). Radiopaque material
(i.e. tantalum or platinum) could also be used in the constituent
wires comprising the mesh. This mesh or braided filter 20 can be
formed from a single mesh/braid layer or from multiple layers
(e.g., a larger porosity layer and a smaller porosity layer). In
another embodiment, the filter is formed from a single solid
material (e.g., a laser-cut tube).
Each of the devices 10, 11, and 13 include one or more struts 22
connected to various locations on the filter 20, to assist in
expanding and contracting the filter 20 during a procedure. Since
the struts 22 are oriented proximally or closest to the delivery
device 30, they act to close the filter 20 as each of the devices
10, 11, and 13 are retracted within the delivery device 30.
The struts 22 and filter 20 are each able to expand over the
deliver wire 12 via a fixed joint 14 and a sliding joint 16. The
struts 22 are connected to the fixed joint 14, which is stationary
relative to the delivery wire 12. The sliding joint 16 is connected
to a distal end of the filter 20, allowing it to slide relative to
the deliver wire 12 as the device expands and contracts.
The filter 20 forms a generally conical shape that functions to
capture thrombus emanating from a more proximal portion of the
vessel. Therefore the open (enlarged) portion of filter 20 is
proximal relative to the portion of the filter connected to the
sliding joint 16, and struts 22 are proximal relative to filter
20.
The devices 10, 11, and 13 can also include a compression member 18
that can assist or bias the device into an expanded position.
Referring to the device 10 shown in FIG. 1, the compression member
18 is disposed over the delivery wire 12 and is connected to
sliding joint 16 and a fixed joint 15, all located distally of the
filter 20. The compression member 18 can include a metal or plastic
spring-like member, a solid resilient polymer member, an elastic
material, or materials with a similar behavior/functionality.
FIG. 4 shows the compressed configuration of the embolic protection
device 10 when positioned in a delivery device 30 (i.e. a
microcatheter). When the filter 20 is collapsed during placement
within a delivery device 30, the filter 20 and struts 22 exert a
force on sliding joint 16. Sliding joint 16 moves distally toward
the fixed joint 15 resulting in compression of the compression
member 18. When the embolic protection device 10 is released from
the delivery device 30, the compression member 18 moves from a
compressed to expanded configuration, proximally pushing the filter
20 and struts 22 to an open or expanded configuration. Since the
filter 20 and/or struts 22 may be composed of shape-memory
materials that are biased or "heat-set" to an expanded
configuration, these components may further exert expansile force
after deployment from the delivery device 30. Further, the fixed
joint 15 anchors the compression member 18, which in turn helps to
create a backstop for over-expansion of the filter 20.
Referring to the device 11 of FIG. 2, the compression member 18
spans the region between sliding joint 16 and the fixed joint 14.
FIG. 5 shows the compressed configuration of the embolic protection
device 11 of FIG. 2 when positioned in a delivery device 30 (i.e. a
microcatheter). When filter 20 is collapsed during placement within
a delivery device 11, the filter 20 and compression member 18 exert
force on sliding joint 16, causing the sliding joint 16 to slide in
a distal direction, stretching out the compression member. When the
device 11 is removed from the delivery device 30, compression
member 18 will exert an unrestrained pulling force between joints
14 and 16, causing the filter 20 to expand, and maintain its
expanded shape. Again, since the filter 20 and/or struts 22 may be
composed of shape-memory materials that are biased or "heat-set" to
an expanded configuration, these components may further exert
expansile force after deployment from the delivery device 30.
Referring to the device 13 in FIG. 3, the compression member 18 is
coupled between sliding joint 16 and distal fixed joint 15 (distal
fixed joint 15 is distal relative to fixed joint 14). In contrast
to the device 10 embodiment shown in FIG. 1, the compression member
18 is located within the filter 20. In contrast to the device 11
embodiment shown in FIG. 2, the compression member 18 only expands
partially between the sliding joint 16 and fixed joint 14.
FIG. 6 shows the compressed configuration of the embolic protection
device 13 of FIG. 3. As the device 13 exits the delivery device 30,
the compression member 18 contracts, pulling the sliding joint 16
proximally towards the fixed joint 15. Again, since the filter 20
and/or struts 22 may be composed of shape-memory materials that are
biased or "heat-set" to an expanded configuration, these components
may further exert expansile force after deployment from the
delivery device 30.
FIG. 7 shows an embodiment of the configuration of distal fixed
joint 15 from FIG. 1. In this embodiment the distal fixed joint 15
has a tapered shape between delivery wire 12 and compression member
18. The fixed joint 15 preferably has a smooth profile and no sharp
edges to help reduce blood vessel trauma as the embolic protection
device 10 is tracked through the vasculature. The profile of the
device is such that it operatively mates with the distal end of
delivery device 30. In FIG. 7, the distal fixed joint 15 sits just
distal to delivery device 30 and mates with the distal opening of
said delivery device 30.
The shape described for the distal fixed joint in FIG. 7 can be
used on sliding joint 16 of device 11 and 13 in FIGS. 2 and 3,
respectively. In this way, the distal-most joint would effectively
function as a `seal` for the rest of the device as its sits in the
delivery device 30.
In one embodiment shown in FIG. 8, the device 15 includes a filter
21 that is inverted from outside-in, creating a flared outer layer
and a reduced inner layer. The filter 21 is pulled inward from a
single layer to create the second, underlying layer. In one
embodiment, a smaller diameter tube is placed internally within the
mesh or braid which forms the filter 20. A portion of the mesh or
braid is then pulled through this smaller diameter tube in order to
create the smaller diameter region of the filter. The filter 20 can
be heat seat into this final shape, the free ends of the filter may
be inserted into a common element (i.e. sliding joint 16), or both
techniques can be used. Alternatively, the filter 21 is created by
placing a larger diameter tube over the external diameter of the
mesh or braid, and then pulling it loosely over said tube to create
the larger flared region.
In another embodiment shown in FIG. 9, the filter 23 of device 17
is inverted from inside-out, forming an inner layer and outer
layer. The filter 23 is pulled and folded outward, over itself to
produce the outer, second layer. The outer layer can be pulled taut
to achieve the lengthier profile shown in FIG. 9 or left loose to
achieve a profile similar to the one shown in FIG. 8. In one
embodiment, a larger diameter tube is placed external to the mesh
or braid which forms the filter. A portion of the mesh or braid is
moved over and around the external diameter of the tube to create
the second, overlapping region. The filter can be heat seat into
this final shape, the free ends of the filter may be inserted into
a common element (i.e. sliding joint 16), or both techniques can be
used. Alternatively, the filter 23 could be created by placing a
smaller diameter tube under the mesh or braid, and then pulling the
mesh or braid tautly under said tube to create the underlying
region.
As previously described, several embodiments described in this
specification include a number of struts 22 that are connected to
and support the filter 20. The struts 22 can help control the
expansion of filter 20 by providing a controlled restraining force.
Since the struts 22, in some embodiments, are connected to fixed
joint 14, they help the filter 20 collapse when re-inserting the
filter 20 into the delivery device 30. During reinsertion, the
struts 22 will provide a restraining force on the filter 20, in
combination with the action of the sliding joint 16 and compression
member 18. Thus the struts 22 help control the filter 20 expansion,
and aid in filter 20 collapse during insertion into the delivery
device 30.
The struts 22 can be constructed in a number of configurations. In
one example, metallic struts 22 can be used with the dual layer
filter 23 shown in FIG. 9. In one example, the struts 22 connect to
both layers of the inverted or everted mesh to provide a stronger
anchor point for the connection. The struts 22 may include a
connecting member 24 (e.g., a hook shape or loop) to connect to the
filter 23. The connecting member 24 may be heat set to form a shape
that connects to the filter 23 or may be directly treated to bond
to the filter 23. In one example, the connecting member 24 is a
coil that encompasses the end of the strut 22 and forms a loop
through a pore of the filter 23. This coil helps secure the strut
22 against the filter 23 and provides a surface which is both
softer and has a higher surface area to push against the filter. A
number of materials can be used for the struts 22, including
Nitinol, stainless steel, polymer, radiopaque materials (i.e.
tantalum, platinum, or palladium) and combinations therein.
In another example embodiment shown in FIG. 11, the struts 22 are
each single wires which extend through pores on the filter 23 and
connect back to themselves, forming an end loop. The end of the
wires can be fixed to themselves via a connecting component such as
a crimped sleeve or can be bonded to each other with an adhesive,
welding, similar technique.
In another example shown in FIG. 12, the one or more struts 22 have
a curved region 26 adapted to mate with a corresponding curved
region of the filter 20. This curved region 26 can extend from a
single strut 22 or between two struts 22 and can further be welded
or heat treated to fix to the corresponding curved region of filter
20. This design allows the force created by retracting into the
delivery device 30 to spread over a larger area of the filter
20.
In another example shown in FIG. 13, the struts 22 are constructed
from a tube (e.g., a laser-cut Nitinol tube) with a tubular end on
one end, and a plurality of fingers on the other end. These fingers
act as the strut 22 and are connected to the edges of the filter
22. In this example, the tubular region opposite the fingers may be
crimped or fixed to the delivery wire 12, thereby acting as a fixed
joint.
FIG. 14 shows another embodiment of an embolic protection device 9
that includes a sliding joint 34 at the proximal end of the device
9 and a second sliding joint 32 at the distal end of the device 9.
A stop 28 is located between the two stops 32 and 34 which limits
the proximal and distal translation of the device 9. In other
words, the device's distal translation is limited by stop 28
interacting with proximal slider 34 (seen in FIG. 15), and the
device's proximal translation is limited by stop 28 interacting
with distal slider 32 (seen in FIG. 16). The sliding joints 32, 34
are disposed or captured around the delivery wire 12 but cause
minimal friction with the wire, thus allowing the joints 32, 34 to
easily slide.
FIGS. 17-18 show an embodiment of a rapid exchange catheter 31 used
for delivery of an embolic protection device 10 (or any of the
devices described in this specification). Catheter 31 includes a
distal port 36 used as an access port for a guidewire 40, which,
when inserted, is used to track or direct delivery of catheter 31
to a certain target region within the vasculature. Proximal port 38
is used as an access port for the embolic protection device 10,
allowing the device 10 to reach the desired target location
achieved by the guidewire 40.
In one example the diameter of guidewire 40 and delivery wire 12
can both be about 0.014''. Various diameters could also be used,
lesser or greater, and this value is only offered as an
example.
Another aspect of the present invention can allow one or more of
the proximal joints 44 and/or distal joints 42 to be rotatable, as
seen in FIGS. 20-24. Preferably, the distal joint 42 is rotatable
to allow rotation of the filter 20 in the vasculature as it expands
and retracts. This allows the device 10 to better conform to the
patient's vessel and reduce any unwanted stress that results in
undesirable functionality of the device 10.
FIG. 20 illustrates one embodiment of a rotatable joint 42A, having
two enlarged sections 46A that are fixed from translation and
rotation to the delivery wire 12. The outer rotational member 42A
may fit directly over the wire 12, thereby capturing the wire 12,
while the enlarged sections 46A prevent translational movement of
the region 42A. Hence, the outer rotational member 42A (and
anything attached to it) can rotate in place.
FIG. 21 illustrates another embodiment of a joint 42B in which the
outer rotational member 43 includes a recessed cavity that
accommodates a fixed, enlarged member 46B. As with the previous
joint 42A, the fixed, enlarged member 46B is fixed to the wire 12
to prevent translational or rotational movement. The member 46B is
also sized large enough such that it is unable to pass through the
reduced diameter portions of the outer rotational member 43. Thus,
the outer rotational member 43 effectively captures the member 46B,
but can rotate in place.
FIG. 22 illustrates another embodiment of a joint 42C that is
generally similar to joint 42A, however, one of the fixed, enlarged
members 46B includes a tapered region while the outer rotational
member 45 includes a reciprocal tapered region. Similarly, FIG. 23
illustrates another embodiment of a joint 42E in which both ends of
the outer rotational member 47 have tapered regions that
reciprocate with two fixed, enlarged members 46C. Finally, FIG. 24
illustrates yet another embodiment of a joint 42E that is generally
similar to joint 42B, but that the outer rotational member 49
includes a tapered, recessed area that captures a reciprocally
tapered fixed, enlarged member 46E.
The joints described may be comprised of a variety of materials
including Nitinol, stainless steel, cobalt chromium, polymer,
radiopaque material (i.e. platinum or tantalum) or various
combinations therein. As previously discussed, these rotational
joints can be used in any of the embodiments discussed in this
specification. Additionally the enlarged members 46A-46E may be
offset (or shrunk in respect to the cavity housing) to allow for
some translational freedom, in addition to rotation.
FIG. 25 illustrates another embodiment of an embolic protection
device 50 that is generally similar to previously described
embodiments, in that the device 50 includes an expandable, conical
filter 64 having a proximal fixed joint 58 and a distal sliding
joint 60. Unlike the previous embodiments, the filter 64 is
disposed over a tube 56 (e.g., a polyimide tube) onto which both
joints 58 and 60 are located and which allows passage for both the
delivery wire 12 and guidewire 40. In this respect, the device 50
functions as a "monorail" or rapid exchange type filter. In one
example delivery wire 12 sits within all or a portion of tube 56
(where tube 56 is placed over said delivery wire), in another
example delivery wire 12 ends at the proximal end of tube 56.
As seen best in FIGS. 25-27, the filter 64 is preferably composed
of a plurality of smaller diameter wires 52 woven with a plurality
of larger diameter wires 54. For example, the smaller diameter
wires 52 may have a diameter in the range of about 0.0005-0.00225
inch while the larger diameter wires 54 may have a diameter in the
range of about 0.00225-0.008 inch. Additionally, about 4 to 16
larger wires 54 can be used and about 72 to 288 smaller diameter
wires 52 can be used. As discussed in further detail below, the
larger diameter wires 54 can also form the struts on the proximal
end of the device 50. In an alternate embodiment, the larger
diameter wires 54 may have the same or similar diameter as wires
52, but may be composed of a stronger or stiffer material (e.g.,
cobalt chromium wires 54 and Nitinol wires 52).
As seen best in FIGS. 25 and 26, when in an expanded configuration,
the filter 64 has a generally conical shape with a less porous end
portion 64A (i.e., the region near the open end). After the device
50 has captured particles during a procedure and the user begins
retracting the filter 64, this end portion 64A expands and reduces
in diameter, following the general shape of the proximal larger
wires 54. At least partial expansion of this end portion 64A can be
seen in FIG. 26. In this respect, the filter 64 cinches or closes
around the proximal portion of any particles caught within the
filter 64 prior to any substantial reduction in diameter of the
remaining, distal portions of the filter 64. In other words, the
proximal end of the filter 64 at least partially closes first,
preventing the distal end of the filter 64 from squeezing out any
of the particles into the patient's vessels. The end portion 64A
can be created by heat setting this area to a more compressed
configuration than the remaining portions, or can be formed from a
varying or different weave pattern. Alternatively, end portion 64A
may have a substantially constant diametric profile rather than the
reduced profile shown.
FIGS. 28-31 illustrate various example steps that can be used to
create the device 50. Referring first to FIG. 29, a tubular
stent-like structure 63 can be first woven or braided with the
previously discussed wires 52 and 54. The center region 64A (also
referred to as end portion 64A in the finished filter 64), is
preferably heat set to a more compressed configuration than the
remaining portions of the tube 63.
Referring to FIG. 30, a proximal end of the tube 63 is crimped on
to tube 56 via fixed joint member 58 and a proximal end of the tube
63 is connected to sliding joint 60 to the tube 56. This
arrangement creates a mesh structure with two conical ends 64B.
Referring to FIG. 31, only the smaller diameter wires 52 are then
trimmed, such that only the larger diameter wires 54 remain on the
proximal end of the device 50. In one example, the wires 52 are
trimmed just proximal of the end portion 64A and against fixed
joint 58. Preferably, as seen in FIG. 28, the free ends of wires 52
around the opening of the filter 64 are electro-polished to reduce
any traumatic or abrasive tendencies. Finally, a second distal,
flexible tube 62 (see FIG. 25) is fixed to the end of the tube 56
to provide the device 50 with an atraumatic tip. Flexible tube 62
may be polymeric (i.e. PTFE) or metallic, and can have a consistent
or variable stiffness profile. A variable stiffness profile would
be useful to have a graduated stiffness along the length of the
tube, where the distal most portion (likely to contact the vessel)
will be more flexible. This variable stiffness profile can be
achieved by using various polymers or metals along the length of
the tube with different material profiles. In one example, a laser
cut spiral pattern is utilized on the metallic or polymeric tube. A
coil may be positioned under the tube, with the polymer heat set
over the coil (i.e. heat shrunk tubing). This coil would provide
additional flexibility to the flexible tube section. Flexible tube
62 contains a channel which the guidewire sits through to enable
tracking through the vasculature.
Optionally, as seen in FIG. 27, one or more radiopaque markers 53
can be fixed at various locations on the filter 64. For example,
markers 53 can be fixed to the larger wires 54 at locations near
the end portion 64A or at the free edge of the filter 64 (i.e.,
near the electro-polished free ends of the wires 52).
FIG. 32 illustrates yet another embodiment of an embolic protection
device 70 that is generally similar to the previously described
embodiments, but further includes a generally parabolic shape of
its filter 72. By providing a more rounded distal end 72A to the
filter 72 instead of a more straight or linear decrease, the pore
size of the filter's mesh can remain more consistent and therefore
improve distal blood flow through it.
FIG. 33, illustrates a distal end view of a filter 76 having a
plurality of struts or larger diameter wires that form a support
basket 78 for the mesh of the filter 76. Generally, the basket 78
provides additional support and even assists in
expansion/contraction of the filter 76. In one embodiment, the wire
of the basket 78 is composed of Nitinol and is heat set to a
desired "open" or expanded configuration. The basket 78 can be
located within the filter 76, woven within the filter's mesh, or
located on and fixed to an outer side of the filter 76.
FIGS. 34 and 35 illustrate another embodiment of an embolic
protection device 80, having a plurality of elongated struts 82
that are fixed to a filter 84. The struts 82 can be heat-set to a
configuration of either the football/elliptical shape of FIG. 34 or
the partially inverted shape of FIG. 35, and can both be compressed
and deployed in those shapes. Alternately, the struts 82 can be
heat-set to have the expanded, partially-inverted shape of FIG. 35,
but can be loaded into a delivery device 30 in the shape of FIG.
34, thereby self-inverting to the shape of FIG. 35 after
deployment. In any of these embodiments, the struts can be formed
by laser-cutting a Nitinol tube to create a "unibody" framework to
help evenly distribute force along a vessel's wall.
FIG. 36 illustrates another embodiment of an embolic protection
device 86 having a generally oval or elliptical shape. This device
86 can be created with a tubular, stent-like structure, having
larger diameter wires 88 and smaller diameter wires 87 woven
together. As with other embodiments described in this
specification, the proximal end can be crimped or connected via a
fixed joint to a delivery wire 12, while the distal end can be
connected via sliding joint to the delivery wire 12.
As previously discussed with regard to the device 50 of FIG. 25,
for example, the proximal-most portion of the devices of this
specification, such as the fixed joint 58, can accommodate both a
delivery wire 12 (which the device is disposed on) as well as a
guidewire 40, which thereby acts as a monorail or rapid exchange
catheter. It should be understood that several different
configurations are possible to accommodate these wires 12, 40,
examples of which are illustrated in FIGS. 37-44.
FIGS. 37-38 illustrate other configurations of rapid exchange
catheter ports involving variations of FIGS. 17-18. The port would
comprise one large opening segmented into two parts, the more
distal port (i.e. 96) would be used for the guidewire while the
more proximal port (i.e. 98) would be used for the embolic
protection device. As shown in FIG. 37 one of the ports could be
perforated (i.e. more distal port 90) to provide some tactile
reference of which port is used for which purpose.
FIGS. 39-40 illustrate various example cross-sectional
configurations of a fixed joint or proximal-most portion of device
embodiments with a rapid exchange capability. In FIG. 39, cross
section 100 includes a first passage 102 and a second passage 104,
where one of the passages may accommodate guidewire 40 and the
other accommodates delivery wire 12. FIG. 40 illustrates a cross
section 106 having a first, round passage 108 for guidewire 40 and
a second arc-shaped passage 110 for the delivery wire 12. In this
example, the delivery wire 12 would also be generally arc-shaped so
as to fit within the passage 110. The passage 110 is also
preferably located relatively close to the passage 108 and has an
inner arc shape that is somewhat larger than the diameter of the
passage 108, reducing the overall diameter of the device.
Turning to FIGS. 41-44, these embodiments disclose various example
port and passage locations. Turning to FIG. 41, a fixed joint 120
is illustrated, having a first port 120C and a second port 120B
that both lead to the same internal passage 120A. Hence, the
delivery wire 12 can pass directly through port 120C, while the
guidewire can pass, somewhat skewed of center via port 40, while
sharing the same passage 120A through the device.
In FIG. 42, the fixed joint 122 includes only a single port 122B
and single passage 122A through the device. Hence, delivery wire 12
and guidewire 40 can share both the port 122B and the passage
122A.
Turning now to FIG. 43, the joint 124 includes a first passage 124A
opening to port 124B, and a second passage 124C opening to port
124D. In this respect, the guidewire 40 can travel through its own
passage 124A and port 124B, while the delivery wire 12 can operate
in passage 124C and passage 124D.
Finally, FIG. 44 illustrates a joint 122 with a single passage 122A
and port 122B, similar to that shown in FIG. 42. However, the
delivery wire 12 further comprises its own internal guidewire
passage 12b that opens proximally at port 12B and near a distal end
of the device. The port 12A is preferably located such that it is
proximal of the joint 122 during normal operation. In this respect,
the guidewire 40 can pass into the device (e.g., through an
atraumatic end) and into a distal end of the wire 12, into its
passage 12B and finally out its port 12A. Preferably, the passage
12B and port 12A are sized so as to accommodate a guidewire 40.
Alternatively, the joint itself may include a port such as port
124B of FIG. 43, and this port leads into a port within the
delivery wire which the guidewire can be inserted through.
Proximal joint 58 and distal joint 60 may have different
configurations as well aside from the fixed proximal, translatable
distal examples discussed earlier. For example, proximal joint 58
may have some translational capability (via one or more stops
placed in proximity to said proximal joint) and/or some rotational
capability via the joint not being complete fixed to tube 56.
Distal joint 60 may have more limited translational capability via
the inclusion of one or more stops placed in the proximity of the
joint, and/or some rotational capability via the joint not being
completely fixed to tube 56.
Another aspect of a delivery device, such as a microcatheter,
allows the distal end of the delivery device to open or expand,
thereby creating a somewhat tapered distal end to facilitate gentle
deployment and retraction of the various embolic protection devices
of this specification. In one example shown in FIGS. 45 and 46, a
cut or slit 136 in a delivery device 130 can be created just prior
to deployment of an embolic protection device. An opening device
134, shaped to cut or rip the wall of the delivery device 130, can
be located at or near the very distal end of the device 130. a wire
132 is connected to the opening device 134 and extends to a
proximal end of the device 130, allowing the physician to pull the
opening device 134, creating a cut. In one embodiment, the wire 132
is located within its own passage within the delivery device 130.
In another embodiment, a perforation is located along the wall of
the delivery device 130 to assist in the creation of the cut. In
another embodiment, the distal end of the delivery device 130
includes a "C" shaped metal component that is biased to outwardly
expand subsequent to creation of the cut 136.
Although the invention has been described in terms of particular
embodiments and applications, one of ordinary skill in the art, in
light of this teaching, can generate additional embodiments and
modifications without departing from the spirit of or exceeding the
scope of the claimed invention. Accordingly, it is to be understood
that the drawings and descriptions herein are proffered by way of
example to facilitate comprehension of the invention and should not
be construed to limit the scope thereof.
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